Exercise could prove key to walking again

Kate Hagan

PARAPLEGIC patients in Melbourne will benefit from a new exercise program that has helped a US man become the world's first paraplegic to stand unaided and walk on a treadmill.

Californian Rob Summers, 25, spent two years retraining his leg muscles before undergoing pioneering surgery to implant electrodes in his spinal cord. The electrodes have been shown to mimic electrical signals sent down the spine by the brain to initiate movement.

Experts describe the finding as a breakthrough, but say more work is needed to establish how many people could benefit and to what extent.

Professor Mary Galea, of the University of Melbourne, said the findings provided renewed impetus for an Australian study into the effects of exercise on recovery after spinal cord injury.

Patients at the Austin Hospital are already going through the exercise program, which involves them being supported in a harness while therapists move their limbs in a walking pattern on a treadmill.

The lead author of the US study, Professor Susan Harkema of the Kentucky Spinal Cord Research Center, visited Australia last year to help train local therapists in the technique.

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Professor Galea said researchers hoped to recruit 188 paraplegic and quadriplegic people into the trial to assess the outcomes for those who exercise their paralysed limbs.

Mr Summers was able to move voluntarily after the electrodes mimicked electrical signals sent down the spine by the brain - but also because nerve networks in the lower spine were able to follow through on those commands without input from the brain.

Those nerve networks in the lower spine were awakened by the exercise program, which allowed his leg muscles to again become accustomed to the sensation of movement.

''What it shows more than anything else … is that the spinal cord below the level of injury retains the potential for control,'' Professor Galea said.

''It shows that if the spinal cord is maintained, then potentially technology [such as the electrodes] can utilise that. But if you allow the spinal cord to deteriorate, which may well happen if it is not stimulated appropriately, then technology in the future may not be able to assist.''

Garvan Institute head of neurodegenerative diseases research Dr Bryce Vissel said: ''There is no question this is a seminal study because it opens up possibilities.

''This patient had a B-level injury, meaning there was some connection between the brain and the spinal cord.

''He needed stimulation to assist, but in the end he could move voluntarily, which is just extraordinary.

''The questions that remain are will this be applicable for people across different types of injuries, and how far they can take it in terms of walking for more than a few minutes.''

Dr Vissel said among the most significant outcomes for Mr Summers was that he regained some sexual, bowel and bladder function. ''The fact [that] that was somewhat restored in this person will bring a lot of hope to a lot of people in its own right.''